Unified Modeling Language 2

Interactions

Modelling with UML, with semantics 140 A first glimpse

sequence

all three are communication semantically diagram equivalent

timing diagram

Modelling with UML, with semantics 141 History and predecessors

• Simple sequence • 1990‘s • Message Sequence Charts (MSCs) used in TelCo-industry • several OO-methods use sequence diagrams

• Complex sequence diagrams • 1996: Complex MSCs introduced in standard MSC96 • 1999: Life Sequence Charts (LSCs)

• Communication diagrams • 1991: used in Booch method • 1994: used in Cook/Daniels: Syntropy

• Timing diagrams • traditionally used in electrical engineering • 1991: used in Booch method • 1993: used in early MSCs

• Interaction overview • 1996: high-level MSCs (graphs of MSCs as notational alternative)

Modelling with UML, with semantics 142 Usage scenarios

• Class/object interactions • design or document message exchange between objects • express synchronous/asynchronous messages, signals and calls, activation, timing constraints

• scenarios • illustrate a use case by concrete scenario • useful in design/documentation of business processes (i.e. analysis phase and reengineering)

• Test cases • describe test cases on all abstraction levels

• Timing specification/documentation

• Interaction overview • organize a large number of interactions in a more visual style • defined as equivalent to using interaction operators

Modelling with UML, with semantics 143 Syntactical variants

• • traditional sequence diagrams + interaction operators • focuses on exchanging many messages in complex patterns among few interaction partners

• Communication diagram • “collaboration diagram” in UML 1.x • focuses on exchanging few messages between (many) interaction partners in complex configuration

• Timing diagram • new in UML 2.0, oscilloscope-type representation, not necessarily metric time • focuses on (real) time and coordinated state change of interaction partners over time

• Interaction overview diagram • looks like restricted diagram, but isn’t • arrange elementary interactions to highlight their interaction

Modelling with UML, with semantics 144 Main concepts

Interaction partner

Lifeline

OccurrenceSpecification reply call aka. EventOccurrence asynchronous signal

Modelling with UML, with semantics 145 Message types

instantiation Event lost & found Messages (i.e.: very slow messages)

non-instantaneous termination Event Message

Modelling with UML, with semantics 146 Activation

external Event

activation bar

activation suspended

warp lines (non-UML)

nested activation

Modelling with UML, with semantics 147 Usage: Use case scenarios

• Interaction participants are actors and systems rather than classes and objects.

• May be refined successively.

• Useful also for specifying high-level non-functional requirements such as response times.

• All kinds of interaction diagrams may be applied, depending on the circumstances.

Modelling with UML, with semantics 148 Usage: Class interactions

• Interaction participants are classes and objects rather than actors and systems.

• Again, successive refinement may be applied in different styles: • break down processing of messages • break down structure of interaction participants.

• All kinds of interaction diagrams may be applied, depending on the circumstances.

Modelling with UML, with semantics 149